Treatment of distillate petroleum



United States Patent 3,125,508 TREATMENT OF DISTELLATE PETRQLEUM FRACTIONS Dennis Geor e Adlington and Kenneth Tnpman, Snnburyoil-Thames, England, assignors to The British Petroleum Company Limited, London, England, a British jointstock corporation No Drawing. Filed Oct. 14, 1960, Ser. No. 62,521 Claims priority, application Great Britain Oct. 20,. 1959 14 Claims. (Cl. 208-264) This invention relates to the treatment of distillate petroleum fractions boiling above 150 C. and particularly to the treatment of distillates boiling between 150 and 450 C., such as 150-250 C., 250-350 C. and 350- 450 C. distillates, and the principal object of the invention is to provide a process by means of which the cloud point, pour point or freezing point of such fractions may be substantially lowered.

According to the process of the present invention, the distillate is contacted in the presence of hydrogen with a catalyst containing a group VIa metal on a refractory oxide support at a temperature of at least 750 F. but below the temperature at which substantial cracking occurs, a pressure which is greater than the equilibrium pressure and a space velocity of the liquid feedstock not exceeding 3 .0 v./v./hr., the temperature and space velocity being correlated so that the cloud point, pour point or freezing point of the stabilized distillate is at least 10 F. lower than the cloud point, pour point or freezing point of the feedstock.

For the purposes of the present specification, substantial cracking is understood to occur when more than 20% wt. of the feedstock is converted to material boiling below 150 C. Preferably not more than 15% wt. of the feedstock is converted to material boiling below 150 C. The temperature employed is preferably above 800 F. and will not usually exceed 900 F. and in general the lower the temperature, the lower the space velocity.

The pressure employed will normally be between 100 and 1500 p.s.i.g. and the hydrogen to hydrocarbon mole ratio will normally be from 5 to 1 to 20 to l.

The process of the present invention will normally lower all the three points specified, viz. cloud point, pour point and freezing point. The point to be taken as the criterion in any given operation will depend on the boiling range of the material being treated and the use to which it is to be put. In general the freezing point is only of significance with the lighter distillates.

By operation at a pressure which is greater equilibrium pressure there will be an overall consumption of hydrogen. given temperature and space velocity is the pressure at which hydrogen consumption and hydrogen production are in balance and may be determined by commencing operation at a relatively low pressure and recycling all than the 7 3,125,508 Patented Mar. 17, 1964 "ice The distillate fraction used as feedstock may have a low initial sulfur content, for example 0.1% wt. sulfur or less. Such low sulfur feedstocks may be straight-run materials or the products of previous refining treatments, for example, products of a hydrocatalytic desulfurization process. With feedstocks containing higher amounts of sulfur, the process according to the invention may result in a considerable reduction in the sulfur content. In the case of feedstocks having a low initial sulfur content, the process may be accompanied by an increase in specific gravity.

Some lower boiling material will be produced by, for example dehydrogenation, desulfurization and/or a small amount of cracking, and this is separated from the product, preferably by fractionation, to stabilized it and give a material of the required boiling range and flash point. 'A convenient cut point is in the region of 130- 170 C.

The catalyst contains a group VIa metal preferably in the form of an oxide or sulfur on a refractory oxide support. The catalyst may also contain a group VIII metal, preferably in the form of an oxide or sulfur, in addition to the group VIa metal. The presence of a group VIII metal is particularly desirable if it is desired to desulfurize as well as to reduce the pour point. The preferred group VIa metal is molybdenum and the preferred group VIII metal is an iron group metal particularly cobalt. The group VIa metal may be present in from 5 to 30% wt. (expressed as oxide), by weight of total catalyst, and the group VIII metal from 0.1 to 5% wt. (expressed as oxide), by weight of total catalyst. A particularly preferred catalyst contains the oxides of cobalt and molybdenum (as such, or in combined form or both).

The refractory oxide support is preferably acidic and may be one or more of the refractory oxides of elements from group II, IE1 or IV. Silica may be excepted from the suitable group IV refractory oxides. It may also contain from 0.1 to 6% wt., by weight of total catalyst, of a halogen, particularly fluorine or chlorine, or 1 to 25% wt. by weight of total catalyst, of phosphorus. Examples of suitable supports are alumina, with or without the stated quantity of halogen or phosphorus, titaniaalumina, zirconia-alumina and beryllia-alurnina.

The catalyst may be employed as a fixed bed, a moving bed, or in the fluidized state.

The degree of reduction in pour point is a function of the catalyst activity and in the case of a fixed bed process,

in which the catalyst is not continuously regenerated, the

The equilibrium pressure for any-- the hydrogen produced without any addition of extra- H neous hydrogen. As the hydrogen produced is recycled the pressure gradually rises until it reaches equilibrium.

The advantages of operating with an overall consumption of hydrogen are principally increased catalyst life, and the minimising or avoidance of a reduction of the diesel index.

Hydrogen may be added on a once-through basis, or it may be recycled.

greatest reduction in pour point is obtained during the early stages of a processing period. In such circumstances, the operating temperature may be gradually increased to compensate for loss of activity. Alternatively, continuous catalyst regeneration may be employed, using either a moving or fluidized catalyst bed process.

If desired, a part only of a particular distillate may be treated by the process according to the invention and the resulting product blended with the untreated portion of the distillate to give a final product of reduced pour point.

The invention will now be described with reference to the following examples:

EXAMPLE 1 A straight run gas oil having a boiling range of 249 of 2.7% wt. cobalt oxide ((300) and 15.5% wt. molybdenum oxide (M on alumina and promoted with 3.34% wt. fluorine, in the presence of recycled hydrogen. The process conditions employed and the results obtained 4 EXAMPLE 3 A vacuum gas oil having a boiling range of 327 C. to 400 C. ASTM was processed over a catalyst consisting are Set out in Table 1 below! 5 of 3.2% wt. cobalt oxide (C00) and 15.0% wt. molyb- Table 1 denum oxide (M00 on alumina and promoted with 3.1% wt. fluorine, in the presence of recycled hydrogen. 0 C (H The process conditions employed and the results obtained pera mg on 1 ions: Temperature, 0 F 680 825 900 ale set out m Table 3 below. Space velocity, v./v./hr 1. O 1.0 8.0 Pressure, p.s.i.g 220 1,000 750 Recycle rate, s.c.f./b 500 6,000 1,000

Feed Table 3 Specific Gravity, 00 F./00 F 0.841 0.833 0.841 0.828 Sulfur content, percent Wt. 1.2 0. 06 0.01 0.05 Pour Point, F +15 +15 15 +15 Hours on Stream Flash Point, O F 235 150 150 150 r d 10 50 100 150 175 This table shows that reductlon of pour pomt 18 not ob- 20 tained under all catalytic hydrogenation conditions which Operating Conditigns: give rise to extensive desulfurization, but that it is necesgfg f g 1 1 1 sary to employ simultaneously a low space velocity and %pace lvocitig, v./vhr./ /b .0 H 0 1.0 '1.0 ecycc as ate, s.f.c. 9750 90 5 9980 9915 a hlgh reactor temperature. Hydrogen Consumption,

2 5 Yieldgvhfl/b 419 440 380 330 86 G tvt 3.9 3." 3.8 5.3 ".8 A vacuum gas 011 havmg a bo1l1ng range of 327 C. to iigfifigf g g Wt 8,3 5,7) 3, 5 5,0 g 1 400 C. ASTM was processed over a catalyst consisting of ii lv per- 87 8 91 3 7 89 89 1 1 2.4% wt. cobalt oxide (C00) and 14.2% wt. molybdenum Stabilized Gas on Inspection 0 i Data: ox1de (M00 n alumma, 1n the presence of recycled Specific Gravity, 600 R] hydrogen. The \PIOCCSS CODdltlODS employed and the re- 0 F Q3915 13545 0 555 03575 1 535 Total sulfur, percent Wt 2.38 0.01 0.01 0.01 0.01 sults obtained are set out in Table 2 below. Y Z o F 60 1 1 1 F'P'F 0151505 Table 2 as oiut, 5 0 0 Hours on Stream 35 Feed 1 Th1s example shows that results slmllar to those 1n Exoperating conditions: ample 2 were obtamed at lower temperatures by usmg a gemperature, F 31 10 908 900 900 900 40 fluorine promoted catalyst. It also demonstrates that the ressure, p.s.i.g 5 61 610 610 605 f Space Velocity, L0 L0 L0 1.0 L0 decline 1n catalyst act1v1ty can be compensated by mcreas Recycle Gas Rate, s.c.f./b 10,200 18,300 9,300 18, 700 18, 700 mg the operatmg temperature. Hydrogen Consumption, Y M s.c.f./b 174 100 191 221 18 S1 x A Gas,percentwt 2.6 3.4 3.1 2.0 E PLE 4 gasolne, psercenlt Wt 8.3 5.3 3.7 4.4 45

it... iltifffiiiiffifffj 89,1 91.3 93,2 93,. A as n g; a lin ra f 4 c. o 0" c. g e Gas Oil Inspection ASTM and contammg 1.13% wt. of sulfur was processed g z' Gravity, over a catalyst consisting of 3.2% wt. cobalt oxide (CoO) SF 32 0869 0-872 25 0-867 0-868 and 15.0% wt. molybdenum oxide (M00 on alumina P013 3,,,%f' f??f ""56 "115 ""15 50 and promoted with 3.1% wt. fluorine, in the presence of Flash Point, F 150 150 150 150 recycled hydrogen. The process conditions employed and the results obtained are set out in Table 4 below:

Table 4 CATALYST Pressure, p.s.i.g 500 500 750 1, 000 750 750 Temperature, F 750 775 825 825 825 825 Space velocity, v./v./hr 1. 1. O 1. 0 1. 0 1. 0 1. 0 Gas Rate (Recycle), s.c.f./b 10,000 10, 000 10,000 10,000 5,000 2, 500 Recycle Gas HzContent, percent vol 8 83 82 73 71 H2 Consumption Yes Yes Yes Yes Yes Yes Feed Product (Unstabilized):

010110 Point, F- 10 2 -10 -8 -15 -2 Pour Point, 5 -5 -15 -15 20 -10 Product (Boiling 150 0.):

Yield, percent wt 94 89. 5 89 85.5 87. 5 SG at 00 Fl60 0. 843 0. 834 0.835 0. 827 0.836 0.835 Diesel Index 60 59 55 62 54 58 Diesel Index- 60 59 55 62 54 .50 0101111 Point, F 18 6 -2 2 -8 2 Pour Point, F 15 5 5 5 15 5 This example shows that a substantial reduction of pour EXAMPLE 5 point is obtained particularly during the early hours on stream.

A gas oil having a boiling range of 234 C. to 350 C.

over a catalyst consisting of 1.4% wt. cobalt oxide (C) and 8.6% wt. molybdenum oxide (M00 on a base of 4% wt. titania and 96% wt. alumina in the presence of recycled hydrogen. The process conditions employed and the results obtained are set out in Table 5 below:

6 not more than 20% wt. of the feedstock is converted to material boiling below 150 C. but not exceeding 3.0 v./v./hr.; maintaining a selected pressure in said zone which is greater than the equilibrium pressure of the 5 feedstock at sa1d selected contacting temperature and sa1d Table 5 CATALYST Pressure, p.s.i.g 500 500 500 500 500 750 1,000 750 750 Temperature, F.-- 750 775 800 825 825 825 825 825 825 Space Velocity, v./v. 1. 0 1. 0 1. 0 1. 0 1. 0 1. 0 1. 0 1. O 1. 0 Gas Rate (Recycle), s.c.f./b 10, 000 10, 000 10, 000 10, 000 10, 000 10, 000 10, 000 5, 000 2, 500 Recycle Gas Hz Content, percent vol 9 83 77 78 82 83 81 78 H1 Consumption Yes Yes Yes Yes Yes Yes Yes Yes Yes Feed Product (Unstabilized):

Cloud Point, F 18 16 4 -2 6 Pour Point, F 10 5 5 5 5 10 -5 10 0 Product (Boiling 150 0.):

Yield, percent wt 91 91. 5 90. 5 90 88. 5 90 SG at 60 F./60 F 0. 834 0. 834 0.830 0. 826 0. 830 0.831

Diesel Index 57 57 60 63 60 60 Cloud Point, F 6 4 6 8 6 10 Pour Point, F 0 0 0 5 0 5 EXAMPLE 6 A petroleum distillate having an ASTM boiling range of 183292 C. was processed over the same catalyst as that used in Example 4. The process conditions were:

Pressure, p.s.i.g. 1,000 Temperature, F 850 Space velocity, v./v./hr. 1.0

Gas recycle rate, s.c.f./b 10,000

Inspection data on the feedstock and products are given in Table 6 below:

We claim:

1. A process for the treatment of distillate petroleum fractions boiling within the range 150-450 C. to lower the pour point at least 10 F. without material reduction in the specific gravity .and diesel index of said distillate fractions, comprising contacting the distillate fraction as feedstock in a treating zone and in the presence of hydrogen with a catalyst containing a group VIa metal on a silica-free, refractory oxide support, the hydrogen to hydrocarbon mole ratio being from 5 to 1 to 20 to 1; maintaining a selected temperature and a selected space velocity in said zone, said selected temperature in said zone being maintained above 800 F. but not higher than about 900 F. and being a temperature at which, at said selected space velocity, not more than 20% wt. of the feedstock is converted to material boiling below 150 C. and said selected space velocity being at least equal to the space velocity at which at said selected temperature selected space velocity but not greater than about 1500 p.s.i. ga., said selected temperature and said selected space velocity being correlated to reduce the pour point of the feedstock such that the pour point of the material of the treated distillate fraction boiling above C. is at least 10 F. lower than the pour point of the feedstock, and recovering the treated distillate fraction.

2. A process as claimed in claim 1, wherein the feedstock contains 0.1% wt. or less of sulfur.

3. A process as claimed in claim 1 wherein the catalyst contains from 5 to 30% wt. (expressed as oxide), by weight of total catalyst, of a group VIa metal on a silicafree refractory oxide support.

4. A process as claimed in claim 3 wherein the catalyst contains from 5 to 30% wt., by weight of total catalyst, of molybdenum oxide (expressed as M00 5. A process as claimed in claim 3 wherein the catalyst contains also from 0.1 to 5% wt. (expressed as oxide), by weight of total catalyst, of a group V111 metal.

6. A process as claimed in claim 5 wherein the group VIII metal is an iron group metal.

7. A process as claimed in claim 6 wherein the catalyst contains from 0.1 to 5% wt., by weight of total catalyst, of cobalt oxide (expressed as C00).

8. A process as claimed in claim 3 wherein the refractory oxide support is selected from the class of supports consisting of the silica-free refractory oxides of elements from group II, III and 1V.

9. A process as claimed in claim 8 wherein the support contains from 0.1 to 6% wt. by weight of total catalyst, of halogen.

10. A process as claimed in claim 8 wherein the support contains from 1 to 25% wt., by weight of total catalyst, of phosphorus.

11. A process as claimed in claim 8 wherein the support is alumina.

12. A process as claimed in claim 8 wherein the support is titania-alumina.

13. A process as claimed in claim 8 wherein the support is zirconia-alumina.

14. A process as claimed in claim 8 wherein the support is beryllia-alumina.

References Cited in the file of this patent UNITED STATES PATENTS UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,125,508 March 17, 1964 Dennis George Adlington et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, line 15 for "stabilized" read stabilize lines 20 and 22, for "sulfur", each occurrence, read sulfide column 3, line 25, for "EXAMPE ,2 i ad ----EXAMPLE 2 same column 3, Table 2, fifth column, line 4 thereof, for

"9,300" read 19,500 same Table 2, seventh column, line 4 thereof, for "18,700" read 14,700 column 4, Table 3, first column, line 4 thereof, for "v./vhr./" read v./v./hr.

--; same Table 5, sixth column, line 5 thereof, for "330" read 300 Signed and sealed this 15th day of February 1966. L)

Attest:

ERNEST W. SWIDER EDWARD -J. BRENNER Attesting Officer I Commissioner of. Patents 

1. A PROCESS FOR THE TREATMENT OF DISTILLATE PETROLEUM FRACTIONS BOILING WITHIN THE RANGE 150-450*C. TO LOWER THE POUR POINT AT LEAST 10*F. WITHOUT MATERIAL REDUCTION IN THE SPECIFIC GRAVITY AND DIESEL INDIX OF SAID DISTILLATE FRACTIONS, COMPRISING CONTACTING THE DISTILLATE FRACTION AS FEEDSTOCK IN A TREATING ZONE AND IN THE PRESENCE OF HYDROGEN WITH A CATALYST CONTAINING A GROUP VIA METAL ON A SILICA-FREE, REFRACTORY OXIDE SUPPORT, THE HYDROGEN TO HYDROCARBON MOLE RATIO BEING FROM 5 TO 1 TO 20 TO 1; MAINTAINING A SELECTED TEMPERATURE AND A SELECTED SPACE VELOCITY IN SAID ZONE, SAID SELECTED TEMPERATURE IN SAID ZONE BEING MAINTAINED ABOVE 800*F. BUT NOT HIGHER THAN ABOUT 900*F. AND BEING A TEMPERATURE AT WHICH, AT SAID SELECTED SPACE VELOCITY, NOT MORE THAN 20% WT. OF THE FEEDSTOCK IS CONVERTED TO MATERIAL BOILING BELOW 150*C. AND SAID SELECTED SPACE VELOCITY BEING AT LEAST EQUAL TO THE SPACE VELOCITY AT WHICH AT SAID SELECTED TEMPERATURE NOT MORE THAN 20% WT. OF THE FEEDSTOCK IS CONVERTED TO MATERIAL BOILING BELOW 150*C. BUT NOT EXCEEDING 3.0 V./V./HR.; MAINTAINING A SELECTED PRESSURE IN SAID ZONE WHICH IS GREATER THAN THE EQUILIBRIUM PRESSURE OF THE FEEDSTOCK AT SAID SELECTED CONTACTING TEMPERATURE AND SAID SELECTED SPACE VELOCITY BUT NOT GREATR THAN ABOUT 1500 P.S.I. GA., SAID SELECTED TEMPERATURE AND SAID SELECTED SPACE VELOCITY BEING CORRELATED TO REDUCE THE POUR POINT OF THE FEEDSTOCK SUCH THAT THE POUR POINT OF THE MATERIAL OF THE TREATED DISTILLATE FRACTION BOILING ABOVE 150*C. IS AT LEAST 10*F. LOWER THAN THE POUR POINT OF THE FEEDSTOCK, AND RECOVERING THE TREATED DISTILLATE FRACTION. 